Tissue resident stem cells: till death do us part

Aging is accompanied by reduced regenerative capacity of all tissues and organs and dysfunction of adult stem cells. Notably, these age-related alterations contribute to distinct pathophysiological characteristics depending on the tissue of origin and function and thus require special attention in a type by type manner. In this paper, we review the current understanding of the mechanisms leading to tissue-specific adult stem cell dysfunction and reduced regenerative capacity with age. A comprehensive investigation of the hematopoietic, the neural, the mesenchymal, and the skeletal stem cells in age-related research highlights that distinct mechanisms are associated with the different types of tissue stem cells. The link between age-related stem cell dysfunction and human pathologies is discussed along with the challenges and the future perspectives in stem cell-based therapies in age-related diseases

Comparison of in vitro Neuronal Differentiation Capacity Between Mouse Epiblast Stem Cells Derived From Nuclear Transfer and Naturally Fertilized Embryos

Somatic cell nuclear transfer (SCNT) can give rise to fertile adults, but the successful perinatal and postnatal developmental rates are inefficient, including delayed developmental behaviors, and respiratory failure. However, the molecular and cellular mechanisms remain elusive. Mouse epiblast stem cells (mEpiSCs) from E5.5-6.5 epiblasts share defining features with human embryonic stem cells (hESCs), providing a new opportunity to study early mammalian development in vitro. In this study, mEpiSCs were established from naturally fertilized mouse embryos (F-mEpiSCs) and SCNT mouse embryos (NT-mEpiSCs). Also, the in vitro neuronal differentiation capacity of F-mEpiSCs and NT-mEpiSCs was compared. Morphology analysis showed less and smaller neurospheres formation and lower percentage of early neurons generation in NT-mEpiSCs. The immunocytochemical analysis and altered mRNA expression levels of the neuronal markers in differentiated cells further confirmed that neurogenesis was slower in NT-mEpiSCs than in F-mEpiSCs. Moreover, neuronal differentiation capacity was correlated with the basal expression levels of Atox1 and Vinculin but not Brachyury and Otx2, emphasizing that developmental aberrations in neurogenesis were associated with the NT technique but not random variations between clones. This study provided an important in vitro platform using mEpiSCs to study early epigenetic and developmental processes associated with neurogenesis

Study on the construction of underground reservoirs on Zhoushan Island and related environmental issues based on the use of typhoon rain

Water resources in the island area vary greatly from year to year and are unevenly distributed within the year, especially during typhoon and rainstorm periods when the lack of reservoirs leads to a large loss of rainfall and flood resources. In order to improve the water resources supply capacity of the island, this paper takes the excavated underground reservoir on Zhoushan Island as the research object to solve the problem of abundant rainfall and flood resources but lack of saving space during the plum and typhoon floods, and to enhance the self-sufficiency of water resources on the island. The study focuses on three environmental issues in the construction of underground reservoirs, and analyses the actual effect of the resourceful use of rainwater floods using the actual measurement data of Typhoon 2106 (In fa) to prove the feasibility of the construction of underground reservoirs. It makes a useful exploration for the future planning and construction of underground reservoirs on Zhoushan Island using underground space resources to solve water shortage

Effect of Chromatin-Remodeling Agents in Hepatic Differentiation of Rat Bone Marrow-Derived Mesenchymal Stem Cells In Vitro and In Vivo

Epigenetic events, including covalent histone modifications and DNA methylation, play fundamental roles in the determination of lineage-specific gene expression and cell fates. The aim of this study was to determine whether the DNA methyltransferase inhibitor (DNMTi) 5-aza-2′-deoxycytidine (5-aza-dC) and the histone deacetylase inhibitor (HDACi) trichostatin A (TSA) promote the hepatic differentiation of rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) and their therapeutic effect on liver damage. 1 μM TSA and 20 μM 5-aza-dC were added to standard hepatogenic medium especially at differentiation and maturation steps and their potential function on hepatic differentiation in vitro and in vivo was determined. Exposure of rBM-MSCs to 1 μM TSA at both the differentiation and maturation steps considerably improved hepatic differentiation. TSA enhanced the development of the hepatocyte shape, promoted the chronological expression of hepatocyte-specific markers, and improved hepatic functions. In contrast, treatment of rBM-MSCs with 20 μM 5-aza-dC alone or in combination with TSA was ineffective in improving hepatic differentiation in vitro. TSA and/or 5-aza-dC derived hepatocytes-like cells failed to improve the therapeutic potential in liver damage. We conclude that HDACis enhance hepatic differentiation in a time-dependent manner, while DNMTis do not induce the hepatic differentiation of rBM-MSCs in vitro. Their in vivo function needs further investigation

Reversal of experimental liver damage after transplantation of stem-derived cells detected by FTIR spectroscopy

The transplantation of autologous BM-MSCs holds great potential for treating end-stage liver diseases. The aim of this study was to compare the efficiency of transplanted rBM-MSCs and rBM-MSC-derived differentiated stem cells (rBM-MSC-DSCs) for suppression of dimethylnitrosamine-injured liver damage in rat model. Synchrotron radiation Fourier-transform infrared (SR-FTIR) microspectroscopy was applied to investigate changes in the macromolecular composition. Transplantation of rBM-MSC-DSCs into liver-injured rats restored their serum albumin level and significantly suppressed transaminase activity as well as the morphological manifestations of liver disease. The regenerative effects of rBM-MSC-DSCs were corroborated unequivocally by the phenotypic difference analysis between liver tissues revealed by infrared spectroscopy. Spectroscopic changes in the spectral region from 1190–970 cm−1 (bands with absorbance maxima at 1150 cm−1, 1081 cm−1, and 1026 cm−1) indicated decreased levels of carbohydrates, in rBM-MSC-DSC-transplanted livers, compared with untreated and rBM-MSC--transplanted animals. Principal component analysis (PCA) of spectra acquired from liver tissue could readily discriminate rBM-MSC-DSC-transplanted animals from the untreated and rBM-MSC-transplanted animals. We conclude that the transplantation of rBM-MSC-DSCs effectively treats liver disease in rats and SR-FTIR microspectroscopy provides important insights into the fundamental biochemical alterations induced by the stem-derived cell transplantation, including an objective “signature” of the regenerative effects of stem cell therapy upon liver injury

Effect of exposed-to-air frequency of cryopreserved embryo on clinical outcomes of vitrified-warmed embryo transfer cycles: a retrospective analysis of 9,200 vitrified-warmed transfer cycles

Abstract Background Cryopreservation of embryos plays a major role in the in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. However, the storage condition of the cryopreserved embryo can change temporarily due to repeated retrieval of the embryo from the liquid nitrogen (LN2) tank during the practical application during cryopreservation. Whether the implantation potential of a cryopreserved embryo will be damaged when the cane containing it is temporarily exposed to air due to the transfer between the LN2 tank and LN2 container is yet to be elucidated. Also, whether the exposed-to-air frequency (EAF) of cryopreserved embryos influences the clinical outcomes is unclear. Objective To investigate whether the EAF of cryopreserved embryo affects the clinical outcomes of vitrified-warmed embryo transfer. Methods A total of 9200 vitrified-warmed embryo transfer cycles were included in this study. All cycles were divided into five groups according to different EAFs (2, 4, 6, 8, or ≥ 10). Post-warming survival rates and clinical outcomes, including implantation, clinical pregnancy and live birth rates were investigated. Kruskal–Wallis test and Pearson’s chi-squared tests were used to compare the patient characteristics and clinical outcomes among the five groups. Furthermore, multivariate logistic regression analyses were conducted to investigate the association between EAF and clinical outcomes. Results No significant differences were observed in the positive HCG rate, implantation rate and live birth rate (P > 0.05) among five EAF groups with respect to D3 embryo, D5 blastocyst and D6 blastocyst. Post-warmed survival rate of D3 embryos (P = 0.015) differed significantly among the five EAF groups, but it was not EAF-dependent. Although clinical pregnancy was different among the five groups with respect to D5 blastocyst (P = 0.042), multivariate logistic regression analysis adjusted for confounding variables suggested that EAF did not adversely affect clinical pregnancy or live birth. Conclusion These findings indicated that human vitrified embryos in the open system could be repeatedly retrieved from the LN2 tank without affecting the implantation potential of the embryo

Study of Catalytic Combustion of Chlorobenzene and Temperature Programmed Reactions over CrCeOx/AlFe Pillared Clay Catalysts

In this study, both AlFe composite pillaring agents and AlFe pillared clays (AlFe-PILC) were synthesized via a facile process developed by our group, after which mixed Cr and Ce precursors were impregnated on AlFe-PILC. Catalytic combustion of organic pollutant chlorobenzene (CB) on CrCe/AlFe-PILC catalysts were systematically studied. AlFe-PILC displayed very high thermal stability and large BET surface area (SBET). After 4 h of calcination at 550 °C, the basal spacing (d001) and SBET of AlFe-PILC was still maintained at 1.91 nm and 318 m2/g, respectively. Large SBET and d001-value, along with the strong interaction between the carrier and active components, improved the adsorption/desorption of CB and O2. When the desorption temperatures of CB and O2 got closer to the CB combustion temperature, the CB conversion could be increased to a higher level. CB combustion on CrCe/AlFe-PILC catalyst was determined using a Langmuir–Hinshelwood mechanism. Adsorption/desorption/oxidation properties were critical to design highly efficient catalysts for CB degradation. Besides, CrCe/AlFe-PILC also displayed good durability for CB combustion, whether in a humid environment or in the presence of volatile organic compound (VOC), making the catalyst an excellent material for eliminating chlorinated VOCs